With the growth of computer networks, electronic mail (email) has become a popular means for both personal and professional communication. Due, in large part, to the proliferation of the Internet, email has become a standard means of communication for billions of people.
A sender uses a Mail User Agent (MUA) to create an email message. Examples of MUAs include client-side applications such as Microsoft Outlook and Mozilla Thunderbird as well as web-based applications such as Hotmail and Gmail. As is well known, the sender creates the email message by entering one or more email addresses, a message subject, a message body and may also attach files to the message. Each email address comprises two portions. A first portion is referred to as a domain of the email address and references a host name or domain name. The domain is typically located to the right of the ‘@’ sign. A second portion is referred to as a username or account name and is used to identify an email account at the domain. The username is typically located to the left of the ‘@’ sign.
The MUA transmits the email message to the recipient, or recipients, via a transmission email server. The transmission email server includes a Mail Submission Agent (MSA) and a Mail Transport Agent (MTA). The MTA contacts a Domain Name System (DNS) to resolve the domain name of the email address and obtain a corresponding Internet Protocol (IP) address. The MTA server uses the obtained IP address to transmit the message to a receiving email server for the recipient. The email message maybe transmitted directly to the receiving email server or it may be relayed via a plurality of Mail Transport Agents (MTAs).
The receiving email server typically includes a MTA, a local delivery agent, local file storage, and a Post Office Protocol (POP) and/or Internet Message Access Protocol (IMAP) server to allow email message retrieval. The recipient uses a MUA to retrieve the email message from the receiving email server.
In a typical American Standard Code for Information Interchange (ASCII) environment all of the components in the network are capable of processing an ASCII email address. However, email addresses in the near future may contain internationalized (non-ASCII) characters. For example, Internationalized Domain Names (IDNs) are defined as Internet domain names that can potentially include non-ASCII characters. It is envisaged that international email addresses may also include internationalized usernames as part of such an email address. Therefore, it is possible that the internationalized usernames may also include non-ASCII characters.
In order to overcome this limitation, a method has been proposed that allows email system components to “downgrade” an internationalized email address. Specifically, an alternate, ASCII email address is defined by a user for an internationalized email addresses. Accordingly, when an ASCII-only system component is encountered, an internationalized email address is downgraded by replacing it with the alternate, ASCII email address before delivering the email to the ASCII-only system component.
This solution enables email messages having internationalized email addresses to be delivered using existing network components.
Accordingly, it is desirable to facilitate the delivery of email messages having internationalized email addresses across a network that may include one or more components that are compatible only with ASCII email addresses without the limitations of the prior art.